I'm not sure what you're saying. I don't know about this "master" or "psys threading code".

Ok so I copy and pasted the details of my latest crash with this file below. Maybe this information can help us?

Process: blender [1462]
Path: /Applications/blender.app/Contents/MacOS/blender
Identifier: org.blenderfoundation.blender
Version: 2.79 (2.79 2018-02-22, Blender Foundation)
Code Type: X86-64 (Native)
Parent Process: ??? [1]
Responsible: blender [1462]
User ID: 501

I attempted to enter the "--debug" commandline into the python console, but I got the following error message:

How do I run blender from that commandline? I'm not familiar with using python or any code within blender.

My apologies.